The invention relates to a process for making otoplasties or adaptive earpieces, consisting of one part or several independently processable parts, which are individually matched to the shape of the auditory canal.
If an adaptive earpiece or, in particular, an otoplasty is to be individually produced today for an in-the-ear nearing aid, this requires a large number of process steps which are extremely time-consuming, work-intensive and thus expensive.
The following work must essentially be performed manually:
1. Production of one more ear impressions of the patient; PA1 2. processing of the ear impression for production of a mold. To do this, excess material must be removed from the ear impression, small flaws in the impression repaired and some parts of the ear impression increased in size. Finally, the ear impression musk be immersed in a wax or similar fluid to smooth the surface. PA1 3. Finally, a mold is made from the ear impression which may consist of plaster, a gel or silicone resin. PA1 4. A polymerizable liquid synthetic resin in the desired mixture is then produced, poured into the mold and polymerized at least partially. If the product is a shell for an individually tailored in-the-ear hearing aid, most of the liquid synthetic resin must be poured out of the mold again before it completely polymerizes. PA1 5. The mold is normally destroyed when the cast is removed from it. PA1 6. The adaptive earpiece or otoplasty is subsequently ground to the correct size and required appearance. PA1 7. Normally, it is then necessary to produce a ventilation channel, which can be done in different ways. PA1 8. After this, a sound outlet opening must be produced by drilling. PA1 9. Finally, the adaptive earpiece or otoplasty must be polished. PA1 10. It must be ensured that there is sufficient space for the hearing aid components (microphone, amplifier, battery, volume control, earphone etc. ). PA1 11. The earphone must be inserted as deep as possible in the part of the otoplasty located in the auditory canal and secured here. Often, there is very little space here to accommodate both the earphone and the ventilation channel, which normally has a circular cross-section, in the part of the otoplasty which is located deep in the auditory canal. PA1 12. In addition, a telephone coil should also be accommodated somewhere inside the otoplasty. PA1 13. In addition, it may be the case that the microphone also has to be located individually. PA1 14. Finally, the cover plate must be secured on the otoplasty, either by bonding or polymerization. PA1 1. completely or almost completely automate production of individually matched adaptive earpieces or housings of in-the-ear hearing aids or otoplasties; PA1 2. permit optimum utilization of the space available in the auditory canal and in the outer ear, with the result that the smallest possible hearing aid can be produced; PA1 3. ensure optimization of position and form of all internal functions and components of an in-the-ear hearing aid and PA1 4. to describe methods for manufacture of well-defined hearing aids and adaptive earpieces of constantly uniform quality, which also appear particularly attractive from a cosmetic point of view at the same time. PA1 a) Direct or indirect tracing of the shape of the auditory canal and conversion of the values obtained into digital form; PA1 b) conversion of the digital representation of this shape into a three dimensional or multi-dimensional computer model of the outer shape of the otoplasty or adaptive earpiece; PA1 c) selection of the various components/functions for the inside of the computer model with simultaneous establishment of the wall thickness and optimization of the positions of the components/functions for best possible operation and minimum bulk; PA1 d) computer-controlled production of an otoplasty or adaptive earpiece from the data thus obtained from the optimized three-dimensional computer representation of the otoplasty or adaptive earpiece.
If the cast is intended for an in-the-ear hearing aid, further process steps are additionally necessary:
Overall, this normally followed method thus consists of a large number of manual process steps which require a great deal of time and which nevertheless involve a good deal of uncertainty, since many of the steps are difficult to monitor and check. The wall thickness and the interior cavity of an otoplasty for in-the-ear hearing aids can be mentioned as examples of this, since these often deviate from the desired values when the manual method is used. In some cases, excess material has to be removed from the interior cavity with a dental drill or grinding wheel in order to create sufficient space for the earphone, ventilation channel etc. However, even this method is not well defined and supplies practically unpredictable results.
For this reason, many attempts have already been made to solve this problem, because in-the-ear hearing aids manufactured using these methods in the past have mostly been of poor quality and possessed hardly foreseeable characteristics.
Modular in-the-ear hearing aids where a module which already contains all components of the hearing aid is molded into an individually produced otoplasty have not proven to be especially successful, probably partly because they are normally slightly larger. This is because the components within the module are arranged in fixed positions. In addition, these hearing aids often had the appearance of composite or hybrid devices. It is the task of the present invention to: